Why is my return clamp heating up?

[arther dailey]

or bolt the cable straight to table ,end of

 

[brightspark]

or bolt the cable straight to table ,end of

or do what i have welded a bolt to a pair of molegrips and fastened a crimp lug on it and the cable no loss of current and overheating there

 

[hotponyshoes]

Borrow a thermal Imaging camera and have a look at it. Ideal for answering questions like this!